In 1838, matthias schleiden published his observation that plant tissues are composed of cells. a year later, theodor schwann published evidence that animal tissues were composed of cells. which part of the cell theory is directly supported by the work of schleiden and schwann?

There are 3 parts of cell theory: all living things are made up of cells, all cells come from pre existing cells, and the cell is the basic unit of life. Since Schleiden and Schwann’s experiments proved that certain tissues were made up of cells (and those tissues are from living organisms), it most closely relates to the part that all living things are made up of cells. Hope this helps! (Also I apologize for the text going italic I’m not sure why it happened)

Both prokaryotic and eukaryotic cells have ribosomes and cell membranes

It is called the medulla oblongata or people usually call it medulla. it is the lower half of the brain stem continuous with the spinal cord.